3.1. Rock Magnetism Results
According to the high-temperature magnetic susceptibility measurements,
the transition of maghemite to magnetite can be seen with an increase in
susceptibility values at approximately 250-350 °C (Fig. 3). The samples
have Curie temperatures between 530 and 550 °C, which may be a sign of
titanium in the minerals and a new sulfite phase created from
decomposing the maghemite and incorporation of the sulfur from the
surrounding clay. The increase in susceptibility values in the cooling
curves corresponds to the percentage of maghemite decrease after heating
(Fig. 3a, c and d). Two different drops in susceptibility values at 410
°C and 530 °C in Fig. 3c show the existence of maghemite and magnetite
together in the sample. The IRM results show that the samples in Fig.
4a-d were saturated at 400-500 mT and demagnetized at 50-60 mT,
indicating low coercivity. Samples in Fig. 4e-h are those that could not
be AF demagnetized up to 100 mT in section 2.4. These samples did not
reach saturation up to 1000 mT and were not demagnetized up to 100 mT,
indicating high coercivity (e.g., hematite). Two samples (17_2M and
22_0M) have Curie temperatures of approximately 540° (Fig. 3c and d),
which shows the presence of both low- and high-coercivity minerals in
these samples.